Count variable not properly counting

[jessho]

Hi,

I am trying to create two different count variables -- PHI_visits (ie. visits when insurance=1) and Medicaid_visits (i.e. visits when insurance=0) -- to count the number of unique patient visits (patcode) with each unique provider (ID) that are with a privately insured patients and Medicaid-covered patients, respectively.  However, I am noticing that the code I am using is creating two count variables that seems to not be counting properly, and I cannot seem to figure out why.

Here is my code:

Data HAmod;
Set IN.HA;
retain ID insurance patcode Medicaid_visits PHI_visits;
by ID;
if first.ID then do;
Medicaid_visits=0;
PHI_visits=0;
end;
if insurance=0 then Medicaid_visits+1;
else if insurance=1 then PHI_visits+1;
Run;

However, when I check the results using proc print, this produces a table as follows:

ID PATCODE insurance Medicaid_visits PHI_visits

65	10	1	0	1
65	15	1	0	3
76	20	1	0	1
111	9	0	1	0
124	30	0	1	0
138	31	0	1	0
166	35	1	0	1
166	47	1	0	3
176	11	1	0	1
196	24	0	1	0
218	50	1	0	1
242	16	1	0	1
242	21	1	0	3

It should instead look like below if PHI_visits and Medicaid_visits are counting correctly:

However, when I check the results using proc print, this produces a table as follows:

ID PATCODE insurance Medicaid_visits PHI_visits

65	10	1	0	1
65	15	1	0	2
76	20	1	0	1
111	9	0	1	0
124	30	0	1	0
138	31	0	1	0
166	35	1	0	1
166	47	1	0	2
176	11	1	0	1
196	24	0	1	0
218	50	1	0	1
242	16	1	0	1
242	21	1	0	2

Would appreciate any help or suggestions. Thanks!

[Reeza]

I think the RETAIN statement is the issue. 

Why do you have ID, insurance and patcode in there? 99% of the time data that already exists should not be in the RETAIN STATEMENT

[Astounding]

Check the incoming data set in.HA.  It probably already contains PHI_visits (and might contain Medicaid_visits as well).  If so, whichever variable(s) already exist should be dropped:

set in.HA (drop=PHI_visits Medicaid_visits);

[Kurt_Bremser]

Make sure that your dataset does not already contain phi_visits. I suspect that is your problem.